186 Forty-first Report on the State Museum. 



been determined by Mr. Howard as au undescribed species of 

 Tridymus Ratz. — a genus very near, in place, to tlie Pteromalince, and 

 not previously recognized in this country. 



First Notice of the Insect. 



Our first knowledge of this gall and its author is found in Baron 

 Osten Sacken's admirable paper " On the North American Cecido- 

 myidse," forming part of the late Dr. Loew's Monographs of the Diptera 

 of North America — Part I, 1862. The gall is thus characterized : 

 " Swelling of the stem and leaf-stalks of the wild grape. This irregu- 

 lar succulent swelling, which becomes red on its stouter and riper 

 portions, extends not only along the stem and leaf-stalks, but also 

 invades the leaf-ribs. It contains round hollows of about 0.1 in. in 

 diameter with an orange-yellow larva in each. Some of the hollows are 

 often abandoned by their inmates and invaded by numerous Thrips." 



The fly has not been figured; its description is as follows : 



Description of the Fly. 



L. vitis O. S. — 0.04 in. long, pale reddish, head blackish, antennae 

 black, apparently 23-jointed, filiform, joints broader than long, sessile, 

 with a short pubescence (they answer exactly Winnertz's figure of the 

 antennae of L. ruhi Wz.), two basal joints yellow, thorax blackish above, 

 with a golden pubescence near the collar and down to the origin of 

 the wings; scutellum pale reddish; abdomen covered superiorly on 

 each segment with rows of blackish scales; legs pale reddish, wings 

 with gray pubescence, anterior margin with a black fringe of hairs 

 {loc. cit., page 202). 



Various Forms of the Galls. 



The figure given on page 184 shows one of the many remarkable 

 forms which this gall assumes. It is from Prof. Eiley's 5th Missouri 

 Report, where he has named it "the grapevine tomato gall," and 

 remarks of it that it is a " most variable gall, being found of all sorts 

 of fantastic shapes, from the single, round, cranberry-like swelling on 

 a tendril, to the large collection of irregular bulbous swellings on the 

 stem or leaf-stalk; sometimes looking not unlike a bunch of cxirrants 

 or a bunch of grapes, but more often like a collection of diminutive 

 tomatoes." From a brief notice accompanying an earlier presentation 

 of the same figure — in the American Entomologist for August, 1869 

 (page 247), it appears that the specimens identified from Ridgewood, 

 N. J., were irregular, compound swellings on the stems and leaves, each 

 swelling being of about the size of a large pea. Such forms certainly 

 could not be suggestive of small tomatoes, nor those illustrated in 

 the figure, nor any that have come under my observation. The com- 

 mon name proposed above for the gall would, therefore, seem to be 

 an inappropriate one. 



